When Sun announced it would offer certain plugins and features for enterprise customers only, and maybe even make them closed-source, the open source community was up in arms. It seems that MySQL and Sun have listened to the criticism, as these plans are now off the table. In fact, these plans did not originate within Sun in the first place.

During the purchase of MySQL AB by Sun earlier this year, Sun promised not to make any changes to the structure of MySQL, but the move to possibly release some parts as closed-source seemed to contradict this. However, these plans did not originate from within Sun at all, they came from MySQL AB, from before the purchase, as a means to increase revenue. Now that MySQL is part of Sun, the move no longer makes sense. "Our initial plans were made for a company considering an IPO, but made less sense in the context of Sun, a large company with a whole family of complementary open-source software and hardware products," said Kaj Arno, MySQL's vice president of community relations, in a post on the MySQL website.

MySQL Server is and will always remain fully functional and open source,

so will the MySQL Connectors, and

so will the main storage engines we ship.

In addition:

MySQL 6.0's pending backup functionality will be open source,

the MyISAM driver for MySQL Backup will be open source, and

the encryption and compression backup features will be open source.

Arno does leave the door open for any possible future proprietary plug-ins and components though, stating that MySQL remains committed to their business model, which allows for both community and commercial add-ons. "We believe the model to be useful for both those who spend money to save time, and those who spend time to save money."